set1 = {2, 4, 6, 8, 9, 5, 1}  # 看起来像是插入顺序

print(set1)
# 检查元素个数
print(len(set1))
print(set1)
# 检查元素是否存在
print(set1)
print(88 in set1)

# 拷贝集合
print(set1)
set_copy = set1.copy()
print(set_copy)

